Mechanical Thrombectomy (Acute Ischemic Stroke)
Mechanical thrombectomy is an endovascular treatment that restores blood flow in acute ischemic stroke caused by large-vessel occlusion by removing the clot from inside the cerebral artery with a catheter. A stent retriever and/or an aspiration catheter is used.
Last updated: 2026-06-09
Definition
Mechanical thrombectomy is an endovascular procedure in which a clot occluding a large cerebral artery is removed mechanically from inside the vessel. Access is usually gained through the groin artery, and the occluded segment is reached under fluoroscopic guidance; the clot is captured by a mesh-like, self-expanding stent retriever or withdrawn with an aspiration catheter. The goal is to reperfuse and salvage brain tissue that has not yet undergone irreversible damage (the penumbra). The method is used in suitable patients in addition to, or as an alternative to, clot-dissolving medication (intravenous thrombolysis).
Indications
Mechanical thrombectomy is considered in patients with acute ischemic stroke and a demonstrated large-vessel occlusion in the anterior circulation (for example, the internal carotid artery or the proximal middle cerebral artery). It is classically performed within the first hours after symptom onset; however, the DAWN and DEFUSE-3 trials showed that the window may extend up to 24 hours in selected patients with salvageable tissue demonstrated on imaging (perfusion/diffusion mismatch). The decision is made by considering the clinical picture (NIHSS), imaging findings, occlusion site, and the patient's baseline independent function together.
Procedure
The procedure is usually performed in an angiography suite under sedation or general anesthesia. A sheath is placed in the groin (femoral) artery and a guide catheter is advanced into the neck vessel. After the occlusion is confirmed by angiography, a microcatheter is passed through the clot. A stent retriever is deployed within the clot to engage it and is then withdrawn together with it; alternatively or in addition, a large-bore aspiration catheter may suction the clot directly. Reopening of the vessel (reperfusion) is confirmed by control angiography. Once adequate recanalization is achieved, the catheters are withdrawn and the access site is closed.
Advantages and Limitations
Mechanical thrombectomy is a treatment supported by randomized trials that can improve functional outcomes by rapidly restoring vessel patency in appropriately selected patients with large-vessel occlusion. Its benefit depends on time and patient selection; the earlier the treatment is delivered and the better the imaging-based selection, the greater the gain. Limitations include the need for an experienced stroke center and interventional team, the fact that not every occlusion can be reopened with this method, and that some damage may remain permanent despite recanalization. Small-vessel occlusions or a largely completed infarct may not be suitable for this method.
Recovery and Risks
Recovery varies greatly with the degree of recanalization, the brain region affected, and the time to treatment. Some patients show marked improvement, while in others neurological deficits may be permanent. Possible risks include vessel injury or perforation, brain hemorrhage (particularly after reperfusion), migration of the clot to another vessel, bleeding at the access site, and contrast-related kidney effects. No outcome is guaranteed; the decision is individualized by considering the patient's clinical status, imaging findings, and expectations together.
References
- Greenberg MS. Greenberg's Handbook of Neurosurgery. 10th ed. Thieme; 2023:1553-1563.
- Rangel-Castilla L, et al, eds. Decision Making in Neurovascular Disease. Thieme; 2018.
- Nogueira RG, et al. Thrombectomy 6 to 24 hours after stroke with a mismatch (DAWN). N Engl J Med. 2018.
- Powers WJ, et al. Guidelines for the early management of patients with acute ischemic stroke. AHA/ASA. Stroke. 2019.
This article is for general information and does not replace a medical examination. Diagnosis and treatment decisions are individual.